REPRODUCTION AND DEVELOPMENT OF THE EASTERN LARCH BEETLE, DENDROCTONUS SIMPLEX LECONTE (COLEOPTERA: SCOLYTIDAE), IN NEWFOUNDLAND

Abstract

AbstractOverwintered adults of Dendroctorms simplex LeConte emerged in May and June and produced one generation and two broods in 1983 and 1984. Egg galleries were vertical, slightly sinuous, and significantly longer in first brood trees than in second brood trees . Females laid zero to four eggs per niche . The average number of eggs per gallery was significantly higher in first brood trees (48) than in second brood trees (31). Mean number of eggs per centimetre of gallery was 1.2 for both broods. Mean brood density was significantly higher in first brood trees (50 individuals per 100 cm2) than in second brood trees (23 per 100 cm2).Dendroctonus simplex has four larval instars. Development from egg to adult in the field averaged 60 and 70 days for first and second broods, respectively. Total development at 12, 18, and 24°C in the laboratory averaged 80, 42, and 39 days, respectively. Adult males were significantly smaller than females.